MOISTURE-PROOF: New trend of dc 12 volt moisture-proof muffin fan that designed for high humidity (80%) cooling ventilation projects,verified test up to 4cm water for 4 hours. DUAL BALL BEARING: 80mm fan 12v big airflow small electric fan with long lasting dual ball bearing provides up to 60000 hours over 6 years life. VARIABLE SPEED CONTROLLER: With a 3.3v-12v speed controller,the small window fan can achieve different airflow (19.5-65CFM) and noise level(21-53.2dBA) according to required. 100V-240V PLUG: Increases the maximum fan speed and enables the fan to be powered through an outlet, just plugging it into an outlet to start the fan. SPECIFICATION: Size: 80x80x38mm;3.15x3.15x1.5inches Dual Ball Bearing Voltage: 3.3-12V Current: 0.09-0.43Amp Air Flow: 19.5-65CFM Noise: 21-53.2dBA Connector: DC 5.5x2.1mm Female. DIY COOLING PROJECT: High airflow 80mm vent fan with double-sided metal grills can be used to cool entertainment cabinet,rv refrigerator and keep elec